Acute knee injuries
Sudden injury to the knee during sports or from a fall can cause trauma to the structures within the knee. Patients will often attend their local accident and emergency department immediately following the injury, have an x-ray which is normal (does not show a fracture or break) and are told they have sprained the knee. They are often discharged or occasionally referred for physiotherapy.
If the knee has locked following the injury and the patient is unable to fully straighten the knee there may be something out of place internally blocking the movement, if this is the case prompt referral to a knee specialist for consideration of surgery is the best course of action.